Active and passive scapulohumeral movement in healthy persons: A comparison

Objectives: Clinical studies investigating shoulder complaints have found t hat active exercises and passive manipulation are not equally effective tre atments, perhaps because active and passive movements align the individual shoulder girdle components differently This study sought to investigate whe ther a significant difference exists in scapulohumeral rhythm of the health y shoulder when the humerus is elevated actively or passively. Study Design: Both shoulders of 10 healthy volunteers (9 men; mean age 50yr s) were studied using an electromagnetic coordinate system to locate the po sition of the scapula relative to the humerus and trunk. Scapula position i n three dimensions was recorded at 10 degrees intervals during active and p assive humeral elevation in the coronal plane between 10 degrees and 50 deg rees, Each shoulder was measured three times. Results: Analysis of variance showed that in all three planes of scapula mo vement (lateral relation, backward tip, and retraction) the components of v ariance attributable to the differences in active and passive movement were less than 5%. Conclusions: During humeral elevation between 10 degrees and 50 degrees no significant difference exists between active and passive shoulder complex m otion in healthy individuals. These findings may help to explain why passiv e manipulation is an effective treatment for shoulder complaints.